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Mark (New Jersey, USA) asked: I have a Nikon D5100 and recently bought a Nikon 70-300mm f/4-5.6G lens with AF but it is not auto-focusing. Am I missing some settings or something is wrong with my camera or the lens?

Hello Mark! Nikon's Autofocus system works by utilizing the motor (to move the lens elements) either inside the lens or inside the camera body. Unfortunately, neither your camera body nor the lens is equipped with such motor. Your lens might be capable of autofocus but the lens elements should be driven by some mechanism to "autofocus" and that is what missing in your combination. In short, the minimum requirement for Autofocus to work is, either the lens or the camera body has to have a focus motor. Lets discuss both of these scenarios one by one.

First scenario: Lens is AF and the camera body has a built-in motor for Autofocus.

The lens you bought is AF lens which stands for Autofocus but it will only autofocus if your camera has a built-in motor inside the camera body. All full frame (FX body) Nikon DSLRs as well as some high end crop sensor (DX body) DSLRs have a built-in AF motor which drives the Autofocus system. Among Nikon DX format (also known as APS-C image sensor format) bodies, D90 and all D7000 series come with the built-in motor inside the camera body but D60, D3000 series and D5000 series do not come with the motor. In case of such consumer DSLRs that do not come with the built-in focus motor, they need to use an AF-S or AF-P Nikkor lens to get the full Autofocus capabilities from the lens itself which we will discuss in our second scenario.

When you attach an AF lens with the camera that has a built-in motor in it, the mechanical coupling between the camera body and the lens is formed by utilizing the screw in the motor and the several pins on the lens (which is connected to the focus ring). When you try to autofocus by pressing the shutter release button half way down, camera uses multiple focus sensors to determine which part of the subject is in focus and which part is not and turns the motor accordingly to adjust the focus. These AF lenses come with their own CPU which gives the focal length, aperture setting and other information to the camera CPU which allows the camera to adjust TTL (Through The Lens) Metering for different shooting modes.

If you want to manually focus while using an AF lens, you have to switch the lever on the camera body (box 1 in the picture above) from AF to M which then disengage the mechanical coupling between the motor and the lens so that you can freely move the lens focusing ring to adjust the focus. In this situation, camera still gets the TTL Metering and different shooting modes data through the lens CPU.

Tip : The DSLR camera bodies that feature a focus motor can use both AF and AF-S or AF-P lenses for Autofocus.

Second scenario: Lens is AF-S or AF-P and the camera body doesn't have a built-in motor for Autofocus.

Nikon's another type of Autofocus lens is called AF-S lens (not to be confused with AF-S focusing mode) which has an Autofocus motor built inside the lens. Those Nikkor AF-S lenses feature Nikon's Silent Wave Motor (SWM) which converts "traveling waves" into rotational energy to focus the optics, according to the Nikon. This enables high-speed auto-focusing extremely accurate and super quiet. You can use Nikon’s AF-S lens with any current Nikon’s camera body whether the body has a focus motor or not, because the lens itself has a built-in focusing motor which controls the focusing function based on the information it gets from the camera’s focusing sensors.

Nikon's third type of Autofocus lens is AF-P lens which uses a “Pulse” motor or “Stepping” Autofocus motor making it even quieter and smoother to autofocus than AF-S lens. According to Nikon, AF-P lenses are ideal when shooting video with a DSLR camera. Some of the Nikon's newer AF-P lenses let you set certain settings from the camera's menu system (VR, AF/MF for example) but on older model lenses, you still have to switch those modes on the lens barrel itself like you do on AF-S lenses. Sometimes, even if your camera supports newer AF-P lenses, you might need to upgrade the camera firmware to be able to set lens’ parameters from the camera menu.

Since the lower end Nikon DSLRs such as D3000 and D5000 series do not have the focus motor built-in, if you want to manually focus using AF-S or AF-P lens, you have to switch the focus mode on the lens barrel from A or M/A to M (box 2 in the picture above) and then rotate the focusing ring on the lens. Since there is no mechanical coupling between the camera body and the lens for Autofocus, most of the higher end lenses let you focus manually in M/A (or A/M in some lenses - works same as M/A but manual focus is less sensitive than M/A) mode as well. The reason behind making such consumer level Digital SLRs without a built-in focus motor is to reduce the size and the weight of the camera for portability.

Conclusion: If you prefer to use Autofocus feature, either you have to upgrade your camera body or the lens if you can't afford upgrading both at the same time. If you want to keep the same body and upgrade your lens and feel comfortable shooting with 70-300mm, you can go with either AF-S or AF-P version of 70-300mm which might be little more expensive than your current lens but you get the VR feature as a bonus. And when you upgrade your body to FX format later, the lens is compatible with the newer body as well.

If upgrading either is not an option at the moment, you can continue using your existing combo and manually focus the lens using the focus ring on the lens barrel. While shooting manually, the green dot, which is visible in the lower left corner of the viewfinder, will confirm that your subject is in focus. When you want to focus, rotate the focus ring on the lens barrel and when it lights up green, the subject is in focus.

I hope this blog helps you to make your decision. Thank you for the question and keep shooting!

When I saw the first image with silky water effect, I thought it was some skillful task accomplished using Photoshop rather than something produced on the camera itself. I was just getting into photography and didn't have much knowledge about various types of photography. After I got my first DSLR, Nikon D60, I started learning the basics of photography; Shutter Speed, ISO, Aperture and was enjoying whatever I could shoot. Actually for the first few months, my expensive DSLR was just a point and shoot camera in Auto Mode. It was only after I learned about various shooting modes and how it works in different light condition, I got interested to dial into them and experiment with the subjects and (objects).

Soon after, I upgraded my DSLR after realizing the limitations and the features that my camera offered. When I bought Nikon D90, I started using external flash units, configured them into remote flash units into group using built-in commander mode and learned other advanced camera settings. Everything was working great but knowing more about different DSLRs and what could it offer enticed me to upgrade myself to my first full frame DSLR, Nikon D700. It was probably one of the best camera I ever owned. It never failed me and always exceeded my expectations. I learned so much about long exposure shots, variety of landscape shots using combination of full frame sensor and wide angle lens and many more other small but very useful photographic techniques. I also learned that the very first silky water image I saw was not any tricks done using Photoshop but the long exposure shot done very carefully by using the combination of camera, wide angle lens, filters and tripod.

After learning about the technique, I went to the nearby falls in Washington DC Metro area to test my knowledge. It was a fail! I learned a very important lesson and that is reading about the technique and actually doing it in practice are two different things. There are so many variables that could contribute to the final image. Our gears and it's setup is what we can control but the ambient, finding good vantage point and getting the right composition is equally important. After many attempts in nearby small water streams, I gained my confidence and went to the Great falls park in Potomac, Maryland last year only to find out that the bridge that I had to cross to get to the fall was closed due to the construction. As soon as the construction was completed and the bridge was opened, I went to the park last Monday (on the Presidents day) and got the shot below. Let me explain in details about how I got this shot.

Long Exposure Effect on Water Falls (click the image to view full size)

When I went there, I tried composing and taking shots on my phone from different angle. Once I found my angle, I setup my camera on the tripod and took one shot. I was shooting in Aperture priority (A) mode at f/11 and since it was a bright daylight time, camera automatically bumped the shutter speed up to compensate the light and froze the water motion. I wanted smooth running (silky water) effect and the only way to get that effect at that time was by using the filter. I attached ND 3 filter (which is 10 stops filter letting in only 1/1000th of the light and requiring 1000 times longer shutter speed to get the same exposure as without the filter) and then the shutter speed got reduced to 6 seconds with an Aperture being fixed of course. After I got home, I exported it to the Lightroom and adjusted the exposure and the color tones little bit. This is one of the main reason I started shooting in RAW mode which gives you an option to adjust settings later on the computer that you missed on site. I hope you like my post and if you have any questions or suggestions, please comment them below.

I have had Nikon D700 for more than five years and loved every bit of it. When it was time for an upgrade, I was looking for a camera with a similar kind of body and controls. After doing much research, I ended up buying Nikon D810 even though Nikon had just announced D850 to upgrade D810. Before getting D810, I was struggling between D750 and D810 but my decision was made easy once I got my hands on both cameras. Even though D750 is newer model than D810, same look and feel and control as my trusted D700 sold me to D810. Some argue that D750 has better dynamic range than D180 but when I was happy shooting with even D700, I was pretty sure that D810 wouldn't disappoint me and it didn't. After I got my camera, I took it to the New York trip this December and got few shots of New York City and some of the city skyline. After I downloaded the pictures on my computer, I was amazed by the dynamic range of this camera and the details it captured. One of my favorite shot from this trip was mid-town New York City view from my hotel room. After having dinner, when I came back to the room, it was already dark and the town was glowing with the city lights. The city view from my room looked amazing and I was excited to capture it. When I took the test shot, I saw some reflections during the playback on the camera LCD screen. I had no choice but to wait little more so that the lights from neighboring rooms and other hotels will start fading and then try another shot. After waiting for few hours, I closed all the lights in my room and increase the camera distance to the glass window so that the camera reflection on the window wouldn't show up on the picture.

Whatever I did at that time to cut down the lights and avoid reflection, it worked and the picture came out with every possible detail I was expecting from 36 Mega-Pixel full frame camera. When I zoomed the picture to 100%, I could even see a person inside distant hotel room. The clarity of the camera sensor is amazing, I love the dynamic range and every detail was visible in the picture. I used Nikon 16-35mm f/4 wide angle lens with the D810 and processed the image using Adobe Lightroom.

Midtown New York City View (click the image to view full size)

Please let me know what do you think of this picture and if you are also shooting with D810, please share your experience with this camera. I always appreciate your feedback or any comments you may have. Happy Shooting!

I must admit that traveling and blogging do not go together and specially if you are traveling into remote areas where Wi-Fi is not readily available. Last couple of months, I was traveling into different places (of Nepal) and realized that not having internet all the time or not updating your social media in every hour or even not having to worry about writing anything removes a lot of pressure from your shoulder and helps you to relax and be more creative. It was a good escape for a couple of months and enjoyed every moment of it. While traveling, few thoughts came into my mind about blogging and how I can incorporate those beautiful landscapes of the himalayan nation but later I chose to stay away from it and enjoy the free moment I had. Sometimes, writing a blog can put lots of pressure and specially when you are running out of the times and topics. First, you have to think about the blog post and then explain it nicely so that you can deliver the message you are trying to deliver to your readers. During the process, you might have to include some visuals (photos, graphs or videos) and that would be an extra work on top of the writing part as well. It's a fun thing to do but surely a time consuming process as well and, if you have another full time job, it becomes very difficult to manage time for the blog regularly. It sounds like an excuse for not being regular on blogging but this is the truth which I learned from my own experience; hard to do full time job and be regular on blogging. Please accept my sincere apology for not being as regular as I wanted to be.

If you were following my blog in last few months, I mentioned about upgrading my Nikon D700 to either D750 or D810. I also mentioned that I was leaning towards D810 for few reasons which I would tell once I get the camera. And the moment is here; I sold my D700 and got the Nikon D810 last month. The main reason I went with D810 and not D750 was same look, feel and control as my trusted D700 even though some believe that D750 has a better dynamic range being newer model than D810 which may be true but I am very happy with D810's capability on every aspect of photography so far. I loved my D700 and the only reason to upgrade was to get little more pixel for cropping and get better dynamic range with the Nikon's newer EXPEED 4 sensor.

SuperMoon (click the image to view full size)

It's been few weeks I am playing with the D810 and I am very happy with my upgrade decision so far. I will be uploading more pictures in coming days but here is the super-moon shot I tried on December 3, Sunday. Please stay tuned and keep guiding me through my mistakes. Happy Shooting!